Adhesive patches can be used for a variety of purposes, including wound protection and/or treatment, continuous transdermal administration of an active ingredient (e.g., a drug), or combinations thereof.
In general, an adhesive patch comprises a support or backing that can be made of a cloth, a plastic film, or the like, and an adhesive layer laminated on the backing. The adhesive patch is generally provided with a release liner laminated on the adhesive layer and packaged in a package (e.g., made of a resin film). In some adhesive patches, components of the adhesive layer can protrude from the edge of the adhesive patch, e.g., via cold flow, which can pose problems during manufacture, shipment, storage, and use. In addition or alternatively, sometimes handling of the patch can cause oozing of the adhesive.
Cold flow can occur depending on the property of an adhesive, and can occur as a result of the adhesive patch being under a load for a long time, for example, when an adhesive patch is contained in a package and stored for a period of time prior to use. Cold flow of the adhesive layer in adhesive patches can inhibit the removal of the adhesive patch from a package, which can be caused by adhesion of protruded adhesive layer components to the inside of the package.